In contrast to traditional planar metal-oxide-semiconductor field-effect transistors (MOS transistors or MOSFETs), non-planar MOSFETs incorporate various vertical transistor structures. One such transistor structure is the “FinFET,” which takes its name from the multiple thin silicon “fins” that are used to form the respective gate channels and that are typically on the order of tens of nanometers in width.
The prior art is replete with different techniques and processes for fabricating MOS transistor semiconductor devices, including both planar and non-planar devices. In accordance with typical fabrication techniques, a MOS transistor integrated circuit is formed by creating a device structure on a semiconductor substrate, where the device structure includes a gate structure, source and drain regions, and a channel region. Some integrated circuit devices are fabricated using a “replacement” gate technique; in accordance with this technique, sacrificial gate material (typically polycrystalline or amorphous silicon) is removed, temporarily forming a trench-like structure (hereinafter “trench”), and then is replaced with a different “replacement” gate material.
With the ongoing scaling of transistor dimensions, gate structure pitches and lengths, as well as tip-to-tip distances between gate structures, must decrease. The decreasing dimensions of gate structures are difficult to attain using typical lithography patterning and etching processes. Etch shrink-related defects further reduce the dimensional accuracy of gate structures formed by conventional lithography at desired technology nodes.
Accordingly, it is desirable to provide integrated circuits having improved gate structures and methods for fabricating integrated circuits having improved gate structures. Further, it is desirable to provide integrated circuits with gate structures separated by tip-to-tip distances having dimensions less than critical dimensions of current lithography techniques. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings, the brief summary, and this background.